First of all, check you email spam folder.
The email could have been flagged as spam by your email cilent.

Our contact form uses the standard WordPress function wp_mail() to send emails.
It requires your web hosting company to allow PHP mail function to work.
Since it’s not working on your website, your web hosting company could have disabled PHP mail function.

You should contact your web hosting and ask them about this issue.
If they only allows SMTP mail, you can ask them for the settings information.
Use the following plugin, which allows setting up of SMTP mail on your website.https://wordpress.org/plugins/wp-mail-smtp/